The Journal of Building and Land Development

EFFECTS OF COVID-19 ON CONSTRUCTION INDUSTRY: A CASE OF INDUSTRY PROFESSIONAL STAKEHOLDERS IN TANZANIA

OMBENI SWAI — 2024-04-10

Post-COVID-19 pandemic studies have been conducted throughout the world. In Tanzania, the studies mostly focus on the health, tourism and economy sectors, but scantly on the construction industry, which contributes significantly to the GDP of Tanzania. The sector contributes about 20% annually to both formal and informal projects. This study intends to investigate the effects of COVID-19 on the construction sector and the corresponding coping strategies applied by the stakeholders during the pandemic. Data was collected using the Kobo Collect Tool (ODK Collect app) from the stakeholders (architects, contractors, engineers, quantity surveyors, realtors, and land surveyors) and analyzed using SPSS (V.29). Findings show that, generally, 96% of all stakeholders experienced the effects. Specifically, 67% decline of projects and clients, 36% disputes due to project delays, 39% office closure and relocation, 26% fear to invest and 28% closed of operations. Coping strategies include staff retrenchment (39%), office relocation (36%) and project postponement (24%). The study recommends a policy promoting locally sourced materials to prevent dependency on imported supplies in the event of another pandemic. Collaborative initiatives between the industry and the government to establish a special fund basket to financially rescue firms during the pandemic are recommended.

Assessment of Significant Risk Factors in Informal Construction Sector in Tanzania: Workers Perception

Sarah Phoya — 2024-04-08

The informal construction sector is plagued by risks above other industries due to its features of being unregulated, unlicensed, and unprotected by the state. These features have consequently resulted in failure by the informal construction sector to cope with the existing risk management framework; as a result, significant risk factors facing this sector are not well established. This paper, therefore, examines the significant risk factors based on the likelihood of occurrence and magnitude of impacts in the informal construction sector in Tanzania. A Questionnaire survey was used to collect data and was administered to 1000 artisans working in the informal construction sector in Dar es Salaam and Mwanza. The 1000 artisans were selected through snowball sampling methods. Investigations involved 19 common risk factors which were identified through literature reviews. Statistical methods were used to analyze the data. A quantitative risk analysis result based on the mean value method and risk prioritization number showed that the five top-ranked risk factors with the highest likelihood of occurrence and highest magnitude of impact were lack of safety gears, none or low wages, manual handling, and lack of welfare facilities. These critical significant factors are from health and safety and financial risk categories. Through a one-simple test, the study reveal that all 19 risk factors were significant to the informal construction. It can be concluded that workers in informal construction sectors are vulnerable to many risks which call for putting in place prevention and mitigation strategies to prevent their occurrence and severity. The study recommends improvement in working conditions of workers in the informal construction sector especially of employment contracts which surface all issues related to health and safety programme, payments, welfare facilities and working tools..

Keywords: Informal construction, Risk factors, Risk assessment, Workers

POTENTIAL OF CASHEW NUT SHELLS IN BIO-BRIQUETTES PRODUCTION IN ADDRESSING HOUSEHOLD HEATING AND COOKING ENERGY DEMAND IN TANZANIA

Nyangi Chacha — 2024-02-15

ABSTRACT

Poor disposal of cashew nut shells contributes to environmental pollution through release of greenhouse gases from their decomposition and burning processes in open dumps. This research explores the potential of transforming cashew nut shells, initially considered waste, into bio-briquettes for household heating and cooking. Cashew nut shells were squeezed using an electric-operated pressing machine to obtain the grits and oil. The study analyzed cashew nut shell grit's combustible properties using proximate analysis and emission tests, and established higher heating values based on the proximate analysis. The proximity test revealed that cashew nut grits have high volatile solids (71.48%), low ash content (2.32%), low moisture content (8.18%) and average fixed carbon (18.01%), indicating potential emissions due to their high volatile solids (VS) value. Higher heating values of cashew nut shell grit was 17.49 MJ/Kg, lower than other studies' values of 20.78KJ/Kg and 27.73KJ/Kg for non-carbonized and carbonized cashew nut shell grits-cake, respectively and 21.9KJ/Kg for coffee husks. Regardless of low higher heating value compared to other feedstock, bio-briquettes produced using cashew nut shells grits can be utilized for household heating and cooking in their original state. Their quality can be enhanced by adding a carbonization process to increase fixed carbon and thereafter higher heating values.

Keywords: Cashew nut shells, Bio-briquettes, Charcoal, Firewood and Energy

Enhancing Utilization of Onsite Household Organic Waste for Biogas Production to Meet Domestic Energy Demand

Minza I. Selele — 2024-01-18

This paper aimed to enhance understanding of utilisation and production of biogas to meet domestic energy needs in urban areas. Biogas is a renewable fuel produced when microorganisms break down organic matter without oxygen. Each type of organic waste has own biogas production yield depending on the characteristics of the substrate. Methodology used in the study involved an inventory survey, interviews, a pilot plant experimental setup and laboratory analysis. The Biogas pilot plant encompassed 2 reactors, each with a capacity of 1m³. One of the reactors was fed with kitchen waste and the other with 1.5kg of kitchen waste and 40L of raw sewage. Results revealed that households can generate an average of 1.5kg/day and 210L/day of kitchen waste and raw sewage, respectively. The COD for kitchen waste, wastewater and Faecal Sludge were 29,163mg/L, 1930mg/L and 32,970 mg/L, respectively. The household’s energy cost was established to be about Tshs 166,830/month. It was established 66.7% of the households use both LPG and charcoal for cooking. A combination of kitchen waste and raw sewage can generate about 0.844m³, covering about 84% of the total household energy demand or 130.7% of cooking time (2.81 hrs). The study concludes that household organic waste can generate biogas, reduce energy costs, address energy shortages and protect the environment. Co-digesting of kitchen waste and raw sewage can save up to Tshs 140,371/month on LPG and charcoal.

Keywords: Kitchen waste, faecal sludge, anaerobic digestion, charcoal, LPG